Growth pattern of Alcyonidium sp.,
an encrusting bryozoan. Drawing by J. Winston, courtesy of American Museum
of Natural History.
Used with permission.

Species Name:Alcyonidium sp.

Common Name:
None

Species Description:Alcyonidium sp. is
an encrusting type of bryozoan, having gelatinous colonies, which form into
whitish or brownish crusts. Zooids are hexagonal or polygonal in shape and
measure 0.46 - 0.22 mm in size. The lophophore measures approximately 0.33
mm in diameter, and has 14 tentacles.

Synonymy:Sarcochiton sp. Hassall,
1841

Other Taxonomic Groupings:
Suborder: Carnosa

II. HABITAT AND
DISTRIBUTION Regional Occurrence:Unknown.

IRL Distribution:Within the Indian River Lagoon, living specimens of
Alcyonidium sp. have been collected in April only at Link Port, Florida
(Winston 1982). Increased sampling effort could potentially widen the documented
occurrence of this species to include other areas of the IRL.

III. LIFE HISTORY AND POPULATION BIOLOGYAge, Size, Lifespan:Zooids in this species are hexagonal or irregularly
polygonal in shape and measure approximately 0.46 - 0.22 mm in length. The
lophophore generally measures 0.331 mm in diameter. Alcyonidium sp. has 14
tentacles.

Abundance:Alcyonidium sp. is
considered rare within the IRL, as it has been collected from only one site.
However, further sampling efforts in other areas could expand our knowledge of Alcyonidium
sp.'s distribution within the IRL. This species is locally abundant at
other locations within its geographic range. In the IRL, it is considered a
fouling organism (Winston 1995).

Embryology:The embryology of Alcyonidium sp. is unknown; however, some
members of this order brood embryos within zooids, while other produce a
cyphonautes-like larva.

IV. PHYSICAL TOLERANCESSalinity:During the time it was collected, Alcyonidium sp. was located at a station where average salinity exceeded 30‰.

V. COMMUNITY ECOLOGYTrophic Mode:Alcyonidium sp.,
like all bryozoans, is a suspension feeder. Each individual zooid in a colony
has 14 ciliated tentacles that are extended to filter phytoplankton less than
0.045 mm in size (about 1/1800 of an inch) from the water column. Bullivant (1967; 1968) showed that the average individual zooid in a colony can clear 8.8ml of water per day.

Habitats:Typical habitat for ectoprocts in the Indian River
Lagoon include seagrasses, drift algae, oyster reef, dock, pilings, breakwaters,
and man-made debris (Winston 1995).

Associated Species:Seagrasses as well as floating macroalgae, provide
support for bryozoan colonies. In turn, bryozoans provide habitat for many
species of juvenile fishes and their invertebrate prey such as Polychaete worms,
amphipods and copepods. (Winston 1995).

Bryozoans are also found in association with other
species that act as support structures: mangrove roots, oyster beds, mussels,
etc.

VI. SPECIAL STATUSSpecial Status:None.

Benefit in IRL:Bryozoans are ecologically important in the Indian
River Lagoon due to their feeding method. As suspension feeders, they act as
living filters in the marine environment. For example, Winston (1995) reported
that bryozoan colonies associated with 1 square meter of seagrasses could
potentially filter and recirculate an average of 48,000 gallons of seawater per
day.